That's because Windows does not have any sandboxing, although that seems to be changing with Windows 10 version 1709.
iOS apps are still sandboxed just like apps from the App Store when you sideload them using Xcode. That's all you would need to install Skype, and sandboxing is what keeps iOS secure, not the App Store. The App Store review is mostly about weeding out obvious junk and enforcing Apple's business model.
iOS apps are still sandboxed just like apps from the App Store when you sideload them using Xcode. That's all you would need to install Skype, and sandboxing is what keeps iOS secure, not the App Store. The App Store review is mostly about weeding out obvious junk and enforcing Apple's business model.